(a) Field of the Invention
This invention relates to systems for switching transformer coupled AC lines and has particular application to space vehicles wherein an umbilical connector couples the audio lines from the launch station to the audio lines in the space vehicle.
(B) Description of the Prior Art
While this invention can have application to various technical fields, wherein AC lines are transformer coupled, it will be illustrated in connection with audio communication lines in space vehicles. Prior to launch, audio lines at the launch station are coupled to audio lines in the space vehicle through an umbilical connector. These audio lines at the launch station are typically transformer coupled to the audio lines in the space vehicle for better noise isolation.
An indepedent switching circuit, whose energization is controlled by a manually operated switch at the control panel of the space vehicle, energizes a switch controller which operates switching means in the audio lines of the space vehicle to connect them to the transformers. Following launch, the switching circuit is manually de-energized to cause the switching means to disconnect the audio lines from the transformers in the space vehicle.
It will be appreciated that immediately following launch, the crew in the space vehicle has numerous operative functions to carry out and, therefore, the need to manually operate a control switch at the control panel for de-energizing the switching circuit constitutes a burden for the crew which this invention intends to remove. The invention also simplifies the space vehicle by eliminating the need for the switch and extra wires leading from the manually operated switch at the space vehicle's control panel to the switching circuit.